秸秆污泥基活性炭的制备及吸附H2S的实验研究

以市政污泥和玉米秸秆的混合物为原材料,KOH为活化剂,制备了秸秆污泥基活性炭(AC).实验考察了秸秆与污泥用量比例,以及活化剂用量对秸秆污泥基活性炭物化特性的影响.结果显示,m(污泥)∶m(秸秆)∶m(KOH)为3∶7∶2的条件下,制备的活性炭C372以微孔为主,微孔率达到0.59,比表面积达到369.271 m2·g-1.该活性炭的穿透硫容与饱和硫容均最高,分别为5.82 mg·g-1(以H2S计)和7.00 mg·g-1(以H2S计),活性炭表面内酯基的存在不利于其对硫化氢的吸附.SEM和BET表征分析显示,随着秸秆在污泥中比例的增加,活性炭比表面积增大,对H2S的吸附量提高.活性炭C372具有较好的再生性能,二次再生后其穿透硫容与饱和硫容均能恢复55%以上.

Preparation of sludge-straw-based activated carbon and its adsorption of H2S

Sewage sludge and corn straw were used to prepare sludge-straw activated carbon (AC) by pyrolysis with KOH. This study investigated the effects of mixing ratio (sludge/straw) and the amount of KOH on physical and chemical properties of the sludge-straw activated carbon. The activated carbon named C372 was prepared with the mixing ratio of sludge:straw:activator of 3:7:2. The microporosity of the C372 was up to 0.59,and the specific surface area reached 369.271 m²·g^-1. The experimental results showed that activated carbon C372 had the highest breakthrough sulfur capacity and saturated sulfur capacity of 5.82 and 7.00 mg H₂S per gram AC,respectively. The presence of the lactone groups on the activated carbon was not conducive to its adsorption to H₂S. The SEM and BET characterization analysis showed that the specific surface area of activated carbon increased as the increase of the proportion of straw in the raw material and the ACs'' adsorption capacity of H₂S. Activated carbon C372 has good regeneration performance,and the breakthrough sulfur capacity and saturated sulfur capacity can be restored more than 55% after the second cycle.